Ipamorelin vs Sermorelin
Two popular GH peptides: selective secretagogue vs classic GHRH fragment.
Anti-agingGrowth HormonePeptideUpdated March 2026
VS
Quick Verdict
Ipamorelin is the more selective GH secretagogue with fewer side effects, while sermorelin is the most clinically studied GHRH peptide with a natural pulsatile release pattern.
Best for
Ipamorelin
Clean, selective GH release with minimal side effects. Better for fat loss and body recomposition.
Best for
Sermorelin
Natural GH restoration with the most clinical data. Better for anti-aging in older adults who want gentle, physiological GH support.
Head-to-Head Comparison
Ipamorelin
Sermorelin
Full Name
Full Name
Ipamorelin (Growth Hormone Secretagogue)
Sermorelin Acetate (GHRH 1-29)
Category
Category
Peptide (Growth Hormone Secretagogue)
Peptide (GHRH Fragment)
Mechanism
Mechanism
Selectively stimulates ghrelin receptor to trigger pulsatile GH release from the pituitary. Minimal effect on cortisol, prolactin, or appetite — highly selective among GH peptides.
Truncated form of natural GHRH (first 29 amino acids). Stimulates the pituitary to produce and release growth hormone in a natural pulsatile pattern. Preserves feedback loops.
Best For
Best For
- • Anti-aging & longevity
- • Improved sleep quality
- • Fat loss & body recomposition
- • Recovery from training
- • Natural GH restoration
- • Improved sleep quality
- • Anti-aging in older adults
- • Gentle introduction to GH therapy
Evidence Level
Evidence Level
Moderate— Phase 2 trials, extensive clinical use data
Strong— FDA-approved (historically), extensive clinical data
Typical Dosing
Typical Dosing
200–300mcg 1–3x daily
Subcutaneous injection, ideally before bed
Subcutaneous injection, ideally before bed
200–500mcg daily at bedtime
Subcutaneous injection, nightly
Subcutaneous injection, nightly
Administration
Administration
Subcutaneous injection, typically at bedtime
Subcutaneous injection, nightly before bed
Time to Effect
Time to Effect
1–2 weeks for sleep; 4–8 weeks for body composition
2–4 weeks for sleep; 8–12 weeks for body composition
Side Effects
Side Effects
Minimal — transient headache, water retention. Very well tolerated.
Injection site reaction, flushing, headache. Generally well tolerated.
Blood Test
Blood Test
Recommended (IGF-1 baseline)
Recommended (IGF-1 baseline)
Price Tier
Price Tier
$$$
$$
ProtocolRx
ProtocolRx
✓ We offer this
✓ We offer this
Which One Should You Choose?
Choose Ipamorelin if you...
- ✓Want anti-aging benefits from growth hormone
- ✓Have trouble sleeping or want deeper sleep
- ✓Want fat loss without muscle loss
- ✓Prefer a gentle, selective GH peptide
- ✓Want to avoid cortisol or appetite spikes
Choose Sermorelin if you...
- ✓Are new to GH peptides and want a gentle start
- ✓Want natural GH restoration (not supraphysiological)
- ✓Are over 40 and want anti-aging benefits
- ✓Prefer the most clinically studied GH peptide
- ✓Want to preserve natural GH feedback loops
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